我能够在我的活动中监听Intent Intent.ACTION_BATTERY_CHANGED
,它的效果非常好。我尝试在清单文件中定义接收器:
<receiver android:name="com.beargreaves.battery.BatteryReceiver">
<intent-filter>
<action android:name="android.intent.action.BATTERY_CHANGED" />
</intent-filter>
</receiver>
但它没有起作用,我在这里读到一篇帖子说必须以编程方式定义。我想在Service中实现注册接收器,而不是在Activity中注册,以便它可以持续监视。我已经成功实现了这一点,并且它运行良好,但我想检查我的工作,看看是否是正确的方法。
我首先扩展了BroadcastReceiver:
public class BatteryReceiver extends BroadcastReceiver{
@Override
public void onReceive(Context context, Intent intent) {
Bundle bundle = intent.getExtras();
if(null == bundle)
return;
boolean isPresent = intent.getBooleanExtra("present", false);
String technology = intent.getStringExtra("technology");
int plugged = intent.getIntExtra("plugged", -1);
int scale = intent.getIntExtra("scale", -1);
int health = intent.getIntExtra("health", 0);
int status = intent.getIntExtra("status", 0);
int rawlevel = intent.getIntExtra("level", -1);
int level = 0;
Log.d("Debug","Battery Receiver OnReceive");
if(isPresent) {
if (rawlevel >= 0 && scale > 0) {
level = (rawlevel * 100) / scale;
Log.d("Debug","BatterReceiver: " + level);
Toast.makeText(context,"Battery Receiver: " + level + "\t" + status + "Raw: " + rawlevel,Toast.LENGTH_LONG).show();
if(level <60) {
/*
* Only invoke the service when level below threshold
*/
Intent i = new Intent(context, BatteryService.class);
i.putExtra("level", level);
context.startService(i);
}
}
}
}
}
然后我使用一个服务在 onCreate()
中注册接收器,然后在 onStart()
中处理事件。如果电量低于阈值,我的广播接收器将启动该服务。
public class BatteryService extends Service {
/*
* First Call to onStart we don't want to do anything
*/
boolean avoidFirst = false;
private BroadcastReceiver receiver;
@Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return null;
}
@Override
public void onCreate() {
super.onCreate();
IntentFilter filter = new IntentFilter(Intent.ACTION_BATTERY_CHANGED);
receiver = new BatteryReceiver();
registerReceiver(receiver, filter);
}
@Override
public void onStart(Intent intent, int startId) {
Log.d("Debug","Battery Service On Start");
int level = intent.getIntExtra("level", -1);
if(avoidFirst) {
if(level != -1) {
Log.d("Debug","Battery Alert Notifying..... " + level);
SMSManager.sendSMS(BatteryService.this, "<number redacted>", "Battery Level Aleart: " + level);
stopSelf();
}
} else {
avoidFirst = true;
}
}
@Override
public void onDestroy() {
// TODO Auto-generated method stub
super.onDestroy();
PreferenceUtil.updatePreference(BatteryService.this, "battery_monitor_on", false);
unregisterReceiver(receiver);
}
}
这是否是正确的方法?首先在onCreate()
中注册接收器,然后在接收事件时启动服务。我尝试了不使用服务,但没有办法注册接收器,因为无法在清单文件中实现。其次,在onReceive()
中发送文本消息时会抛出异常。据我所读,onReceive()
不应启动任何线程。
提前致谢。